This invention provides waste paint solidifying compositions and methods for environmentally-friendly paint disposal. The waste paint solidifying compositions are fast-acting and comprise sodium carboxymethylcellulose as a chemical thickener to solidify latex or acrylic paint. The compositions can be used to treat water-based waste streams such as paints, textures, joint compounds, and coatings for disposal in accordance with applicable environmental and government regulations. Methods for non-toxic disposal of latex or acrylic paint are provided as well.
Extrapolating data from several states, the U.S. Environmental Protection Agency (EPA) calculates that between 35 and 103 million gallons of paint are disposed of each year. While the EPA does not classify latex paint as hazardous waste, most waste disposal facilities will not accept paint of any kind unless the paint is completely solidified. Liquid latex paint can cause huge cleanup problems such as contamination of ground water or when cans with liquid paint are crushed during transportation to a landfield and the paint leaks out onto roadways.
Construction industry utilizes liquid latex and acrylic paints and various water-based latex and acrylic products such as, for example, as water-based coatings, primers, textures and joint compounds. However, these products may not be disposed of as liquids. One solution for proper disposal is to solidify waste paints by adding an absorbent material.
Many commercially available solidifiers use sodium polyacrylate crystals to dispose of water-based paints and colorants. For example, US patent publication 2002/0147378 discloses the use of a swellable polyacrylate to solidify liquid paints. Other known paint solidifiers use pelletized corn cobs, or absorbents like clay, sand, or vermiculite and include solidifiers disclosed in US patent publication 2012/0073470. However, many of these solidifiers take several hours to absorb a liquid paint and some solidifiers need to be used in large amounts, which increases dramatically the amount of waste generated. Thus, there remains the need for non-toxic paint solidifiers which can solidify expeditiously acrylic and latex liquid paints without increasing significantly the amount of solid waste generated in the process.